In the transition of an electron in an atom,its kinetic energy changes from $y$ to $y/4$. The change in $P.E.$ will be

Which of the following arrangements of electrons is most likely to be stable?

Match the equations given in List-$I$ with their names in List-$II$.

List-$I$	List-$II$
$(1)$ $\Delta x \cdot \Delta p \ge \frac{h}{4\pi}$	$(A)$ De Broglie equation
$(2)$ $mvr \ge \frac{nh}{2\pi}$	$(B)$ Uncertainty principle
$(3)$ $\lambda = \frac{h}{\sqrt{2m(KE)}}$	$(C)$ Frequency equation of $H$-spectrum
$(4)$ $\nu = 3.29 \times 10^{15} \left( \frac{1}{n_i^2} - \frac{1}{n_f^2} \right)$	$(D)$ Angular momentum is quantized

Which of the following statements is $CORRECT$ :
$(I)$ Where orbitals are available in degenerate sets,maximum spin multiplicity is observed.
$(II)$ Where two electrons occupy the same shell,they may have same spins.
$(III)$ All noble gases do not have the same valence shell electronic configuration.

In $H$ atom,an orbit has a diameter of about $16.92 \ \mathring{A}$. What is the maximum number of electrons that can be accommodated in this orbit?

Match the following items:

$A$. Energy of ground state of $He^+$	$i$. $+6.04 \text{ eV}$
$B$. Potential energy of $I$ orbit of $H$ atom	$ii$. $-27.2 \text{ eV}$
$C$. Kinetic energy of $II$ excited state of $He^+$	$iii$. $8.72 \times 10^{-18} \text{ J}$
$D$. Ionization potential of $He^+$	$iv$. $-54.4 \text{ eV}$